Joseph is correct – Gelt is the way to go for the Rebbe and morah and for the kinder.
as an interesting side note: R’ M.M. Weiss mentioned on one of his tapes that we always tell our children the importance of tzedaka however generally speaking kids do not have money. He mentioned that a way to teach the lesson is that when the children receive Chanukah gelt the parents should show them how to separate off the correct amount and to give it to tzedaka. As an example, he mentioned to go to the local grocer and ask him to put the money on the account of a rebbe that is having trouble paying his bill (in the small grocery stores the owners know which accounts to apply the money).